Sensory substitution advocates benefit from advances in science and technology in attempting to adapt the remaining faculties of the sensorially deprived to compensate for or replace diminished or lost faculties. The best hope lies in the use of senses having a bandwidth nearest the bandwidth of the lost faculty. The most promising approaches minimize the need for mental interpretation and translation.
Substitution of hearing for sight has received much attention since hearing has a bandwidth most nearly equal to that of sight. Mammals are accustomed to interpretation of sound in spatial relation to their surroundings. Prior efforts have largely been addressed to the analysis of the production of faithful reproduction of sound while considering the available sources and room acoustics. Analyses of the capabilities of the human ear have also been widely studied. Developments addressed to utilization of the ears have confined attention to the plane of the ears.
A given visual scene can be described as a three dimensional matrix in either Cartesian or polar coordinates. Paintings, drawings and photographs usually reduce the coordinates from three to two. Humans are so accustomed to a two coordinate representation that no new mental translations are required.
The present invention involves production of a two dimensional analog in the medial plane of three dimensional surroundings. A third dimension may be made available.
The invention involves effectively a vertical array of electroacoustic transducers, as at the corners of a picture frame, rather than horizontal arrays used in quadraphonic hi-fi.
It has been shown that virtual sound sources can be displaced at will in either or both the pinnal and medial planes. A hearer readily identifies the coordinates of such a virtual source. In accordance with this invention, inputs to several transducers are shifted in phase and/or amplitude in response to signals produced from the selected scan acquisition information.